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View Full Version : Now I've Gone and Done it - BP Mill Specialist Needed!



CCWKen
02-15-2018, 05:53 PM
:mad:
Going back to yesterday: I was making sure the new knee feed stops were set to the knee maximum travel for my Z-Axis scales and that the tied up wiring for the feed would make the trip up and down ok. In the process, I didn't realize I was over the vise and the Knee Feed motor stalled then stopped when the circuit breaker on the feed tripped. I reset the CB, lowered the table and moved the X-Axis to clear the vise. All went well with the up and down of the knee using the feed.

Jump forward to today: I drove the Quill up into the head about 3/8". This is an estimate and a guess by looking at the Quill Nosepiece. It's sitting inside the column where I used to see a few thousandths gap between the Cap and the Quill. Also, the Quill Feed Handle is locked up. The Spindle will still turn and in fact I started the motor expecting to find my zero-Z by touching-off on top of a part when I found I couldn't move the Quill Feed Handle. At that point, I recalled yesterday's event. I didn't climb up to look at the top side but my RPM meter was working and it's attached at the top. The drawbar seemed to be sitting higher though.

Question: How do I drive the Quill back down to where it's supposed to be? :o
Can I just whack on the drawbar?

Anyone that says the ASong Knee Feed isn't strong enough didn't install it correctly. :cool:

chipmaker4130
02-15-2018, 06:59 PM
Does your machine have 'rapid' handle feed, or just fine feed? If you have the rapid, you might have run the pinion beyond the rack. Probably did some damage but you may be able to force the handle/wheel back into engagement, then fix the teeth.

OR maybe I'm not understanding what happened.

BTW, I'm NOT a specialist anything, so don't do anything I suggest until said specialist chimes in!

CCWKen
02-15-2018, 07:10 PM
It has both fine feed and handle feed. My first thought was the rack on the column was jammed on the handle feed but I was able to remove the handle feed shaft without difficulty. The gear on the shaft looks ok. I'm pretty sure I displaced the bearings at the lower column. I know that to remove the spindle you just remove the collar at the bottom and rap on the drawbar. I was hoping that leaving the collar in place and rapping on the drawbar would push the whole quill back down but wanted to ask first.

chipmaker4130
02-15-2018, 07:13 PM
Oh, shoot! Well, I hope that works, and that someone will come along with experience in that matter. It must've happened before.

CCWKen
02-15-2018, 07:14 PM
Yeah, I know--I get a "Clumsy Bastard" for this one. :o

3 Phase Lightbulb
02-15-2018, 08:21 PM
Sounds like you pushed the brake shoe up and out of the spindle pulley. It's probably expanded outside on the top of the pulley now. I would remove the low gear disengagement ring cam on the top of the spindle, then unscrew the locknut for the upper bearing and sleeve, pull the bearings and sleeve, remove the retaining bolts then compress the brake shoe and push it back down into the spindle pulley.

3 Phase Lightbulb
02-15-2018, 08:29 PM
Yeah, I know--I get a "Clumsy Bastard" for this one. :o

I think something stronger than "Clumsy" is more appropriate for this one :)

wierdscience
02-15-2018, 10:18 PM
It's probably stuck solid in the quill housing bore.If the spindle bearings are good and you hope to get lucky and not have to replace them.What I would do is separate the motor drive from the quill housing,remove the feed worm assembly and find a piece of round pipe or tubing to use as a driver to apply the force directly to the quill and not hammer on the shaft and bearings.

CCWKen
02-15-2018, 11:57 PM
Thanks guys. I'll be looking it over in more detail tomorrow. I don't think the brake is out of place as I used it to remove the end mill and collet I was "about to use" on a quickie job. It held, locked and released as usual.

Oh man, I started thinking of all those gears and widgets for the down feed. I hope I didn't break something in there that jammed the quill. Well if there's anything positive that can come from this, I might be able to get my RPM sensor mounted to read the actual spindle rpm instead of off the top bearing nut. (Which turns at motor/pulley speed regardless of back gear engagement.)

Thanks again. I'll report on the autopsy tomorrow. :cool:

_Paul_
02-16-2018, 08:13 AM
Good luck with the jammed quill Ken, could it be the quill pinion is damaged?

Wouldn't mind seeing how and where you mount the sensor for your Tacho not too many good places on a BP.

Paul

Sparky_NY
02-16-2018, 08:38 AM
Good luck with the jammed quill Ken, could it be the quill pinion is damaged?

Wouldn't mind seeing how and where you mount the sensor for your Tacho not too many good places on a BP.

Paul

A friend with a machine shop had a bridgeport with the quill jammed tight. It was the pinion gear/shaft. The rack is machined right into the quill housing. I gave him a old bridgeport head for parts and he fixed it but had a lot of trouble getting it apart due to being jammed up. My bet is you stripped that pinion gear and the pieces are jamming things up tight. Get a exploded view of a BP head from online.

CCWKen
02-16-2018, 09:31 AM
I was looking at an exploded view last night and don't understand how the quill could have moved up at all with the Quill Stop Knob in place (#163 on my drawing). I'm now thinking that it sheered the cap screw holding that to the quill and the screw remnants have jammed the quill. I hope it's that simple. I'm headed to the shop now so I'll be back around lunch time.

3 Phase Lightbulb
02-16-2018, 09:37 AM
I was looking at an exploded view last night and don't understand how the quill could have moved up at all with the Quill Stop Knob in place (#163 on my drawing). I'm now thinking that it sheered the cap screw holding that to the quill and the screw remnants have jammed the quill. I hope it's that simple. I'm headed to the shop now so I'll be back around lunch time.

I hope it's something simple. For lunch, you should try the TB Nacho Fries.

CCWKen
02-16-2018, 01:52 PM
Close--I'm having ham and cheese on a tortilla smeared with bean dip and Fritos on the side. I'm washing it down with Big Red. :)

As far as the mill, it's not simple. :( The cap screw and quill stop were intact. I already had the quill feed handle and shaft out so started looking at the auto down feed. I can engage the down feed and turn the drive pulley by hand. The worm gear that drives the handle shaft turns and I can reverse the feed and slip it into neutral so it's strictly the Quill that's jammed in the column. Looks like I have a major disassembly ahead. I already removed the motor but I'll have to watch a few videos and maybe get a manual before I start taking more parts off the top. Dang, and that motor was heavy too!

3 Phase Lightbulb
02-16-2018, 01:58 PM
Close--I'm having ham and cheese on a tortilla smeared with bean dip and Fritos on the side. I'm washing it down with Big Red. :)

As far as the mill, it's not simple. :( The cap screw and quill stop were intact. I already had the quill feed handle and shaft out so started looking at the auto down feed. I can engage the down feed and turn the drive pulley by hand. The worm gear that drives the handle shaft turns and I can reverse the feed and slip it into neutral so it's strictly the Quill that's jammed in the column. Looks like I have a major disassembly ahead. I already removed the motor but I'll have to watch a few videos and maybe get a manual before I start taking more parts off the top. Dang, and that motor was heavy too!

That sucks. I have some bridgeport manuals online here if you need any.

http://www.bbssystem.com/viewtopic.php?t=62

boslab
02-16-2018, 03:00 PM
I'm damn sure I read about the quill problem on another site a while ago, I don't have a BP I have its wimpy cousin the Cincinnati, anyway I will try to remember where but from what I read it was a simple fix, think it required disengaging somthing to re rack the quil.
I'm sure it will be ok, you can always stick an extender in!
Mark

CCWKen
02-16-2018, 03:10 PM
Thanks! I downloaded the 1966 Manual and the J-head diagram but they don't cover disassembly. I went ahead and ordered a "Renovation Guide" off Ebay that's supposed to cover rebuilding. It's more like a shop manual rather than owner/operator manual. It's 127 pages with lots of photos so we'll see. In the meantime, I'll have to make work space and check the juice in the parts washer. :cool:

CCWKen
02-16-2018, 03:15 PM
Thanks Mark. I'm sure I'm not the only one that's run the quill into the table. :rolleyes: I'm just glad it wasn't running at the time. :o

Joe Rogers
02-16-2018, 04:28 PM
May have turned out better. Then you might have a trophy hole in the table instead.
Joe

Daveb
02-17-2018, 04:31 PM
I don't see how the quill could have moved up far enough to damage anything or jam. The depth stop should limit up/down movement because it runs in a closed slot. Are you sure the quill lock is not engaged? Are you sure the power down/up feed is not engaged?

Dan_the_Chemist
02-17-2018, 04:51 PM
I hate to tell you this but it's dead. However, there is one bit of good news. Since you seem like a nice guy I'll waive my normal collection fee and pick it up and bury it for free.

CCWKen
02-17-2018, 05:20 PM
Book or no book, I started into it thinking I'd be finding broken parts. Turns out it was simple but I didn't find it until I had the entire top end off. Not finding anything wrong on the top side I decided to pull the spindle and quill. Out came the spindle without having to lock the quill. I'm thinking that quill is jammed in there pretty good and going to be problem. I fashioned a puller out of all-thread with a 3" pulley and nut/washer on top of the quill. To do the pulling, I just clamped the other end of the all-thread in the vise and lowered the knee. The quill was creaking and burping all the way out. But just as the power knee feed (and me) started the problem, I used the power feed to pull the quill out of the head.

Turned out to be the Quill Nosepiece (#172) or more specifically, the set screw that locks it. It was out just enough to stop the quill from fully returning. In the past, I wondered why I didn't seem to have full travel. Apparently, the set screw has been interfering with complete quill return for some time. When the I ran the quill into the vise, the set screw raised a burr on the edge of the housing and a channel up about 3/4" on the inside. All I did was use a Dremel with a 240 grit sanding drum and clean the burr out. That was it. :D

I'll be spending the next day or so cleaning and painting parts before I assemble the head. I also want to get the Tach Sensor installed inside the head. Looks like the best place for that is above the bull gear. There's enough space above the cover plate (and clear the pulleys) to mount the sensor and I'll drill a hole in the bull gear then epoxy the magnet there. I can run the sensor lead out through the oiler relief in the cover.

http://bbs.homeshopmachinist.net/attachment.php?attachmentid=2357&d=1518910045

chipmaker4130
02-17-2018, 08:56 PM
Well then! I'd say that's good news, and one to 'file away' for later. Glad it won't cost you more than your time.

duckman
02-17-2018, 09:01 PM
But you need to remember if you tighten the set screw to much you make the end of the quill egg shaped and it still won't go up until you jam it, been repairing BRPT's for about 40+ years. Did you take the screws out of the top of the quill that pull the thin dirt sleeve down with the quill if not you bent the tabs and you have to open up the head to fix them, sorry.

CCWKen
02-17-2018, 10:53 PM
Yes, I removed the sleeve and oil wick over the quill before pulling the quill.

Yes, I was aware of over tightening the set screw.

Where were you when I needed you? :)